Effects of grab bars and backrests on independent wheelchair transfer performance and technique

OBJECTIVE

For individuals who rely on wheeled mobility devices for primary mobility, the ability to transfer independently greatly enhances participation in activities within and outside of the home. Nonlevel transfers are challenging and inevitable as not all surfaces in all settings can be made level with an individual's seat to floor height. The purpose of this study was to investigate the effects of two transfer aids, grab bars, and backrests, on the performance and quality of nonlevel transfers.

METHODS

This study employed a repeated-measures design with transfer setup as the independent variable. Sixty-eight (53 men and 15 women) wheeled mobility device users performed level and nonlevel transfers to a bare surface, a surface with grab bars present, a surface with grab bars, and a backrest present. For each condition, participants were asked to transfer as high and as low as they could go while still performing an independent and safe transfer. The transfer assessment instrument was used to evaluate the quality of their transfer technique.

RESULTS

Participants were able to transfer an absolute height up to 2.5 cm (1″) higher and lower when grab bars or grab bars and a backrest were present on the surface (p < 0.042) and 2.3 cm (~1″) higher relative to their wheelchair level seat high when grab bars were present on the surface (p < .001). Transfer technique significantly improved for both uphill and downhill transfers with the presence of grab bars and a backrest as shown by the transfer assessment instrument scores (p < 0.046).

CONCLUSIONS

The presence of grab bars and a backrest on transfer surfaces may help mobility device users to achieve higher and lower absolute transfer heights and facilitate better transfer technique.

Participation in science and engineering laboratories for students with physical disabilities: survey development and psychometrics

Purpose: The purpose of this study is to address the development of the Full Participation Science and Engineering Accessibility (FPSEA) self-report survey that gathers experiences from students with physical disabilities (SwD-P) using a postsecondary laboratory and to evaluate the survey's stability. Methods: Survey items were generated from an extensive literature review and recommendations articulated by experts. Think-aloud sessions and content validity index (CVI) were used to determine survey content validity and help finalize survey items. Individuals with physical disabilities (n = 20) who have taken a postsecondary science or engineering laboratory course completed the survey and took it again 10-14 days apart. The test-retest reliability was assessed using Spearman Rho coefficients for Likert-scale items, Chi-square and Fisher's exact test for the dichotomous items. Missing data completely at random (MCAR) test was computed before reliability data analysis. Results: Each sub-item passed the MCAR test, indicating that the data are missing completely at random and can be imputed to perform the analysis. Reliability analysis was completed on 20 individuals. The FPSEA had good content reliability: the item-level CVI of items kept ranged from 0.86 to 1. The scale-level CVI was 0.94. Stability was demonstrated with adequate Spearman correlation ranged from 0.56 to 0.86. Conclusions: No previous survey had been developed linking SwD-P and the postsecondary science and engineering (S&E) laboratory setting prior to this work. Overall, FPSEA is reliable and stable for reporting the barriers and facilitators to use S&E laboratories from the SwD-P's perspective. Implications for rehabilitation The barriers students with disabilities encounter in S&E laboratory environments are largely unknown. The FPSEA survey may help identify barriers and facilitators to using S&E laboratories for SwD-P. The FPSEA Survey allows former and current SwD-P to share their experiences using a postsecondary S&E instructional laboratory.

Integration of Pneumatic Technology in Powered Mobility Devices

Advances in electric motors, electronics, and control systems have enhanced the capability and drivability of electric power mobility devices over the last 60 years. Yet, battery technologies used in powered mobility devices (PMDs) have not kept pace. Recent advances in pneumatic technology, primarily the high torque, low speed design of rotary piston air motors, directly align with the needs of PMD. Pneumatic technology has advantages over battery-powered technology, including lighter weight, lower operating costs, decreased environmental impact, better reliability, and increased safety. Two prototypes were created that incorporated rotary piston air motors, high-pressure air tanks, and air-pressure regulators. Prototype 1 was created by modifying an existing electric PMD. Range tests were performed to determine the feasibility of pneumatic technology and the optimal combination of components to allow the longest range possible at acceptable speeds over ideal conditions. Using a 1.44 L air tank for feasibility testing, prototype 1 was capable of traveling 800 m, which confirmed the feasibility of pneumatic technology usage in PMDs. Prototype 2 was designed based on the testing results from prototype 1. After further optimization of prototype 2, the average maximum range was 3,150 m. Prototype 2 is up to 28.3% lighter than an equivalent size electric PMD and can be fully recharged in approximately 2 minutes. It decreases the cost of PMDs by approximately $1,500, because batteries do not need to be replaced over the lifetime of the device. The results provide justification for the use of pneumatic technology in PMDs.

The future of the provision process for mobility assistive technology: a survey of providers

PURPOSE

The purpose of this study was to evaluate the opinions of providers of mobility assistive technologies to help inform a research agenda and set priorities.

MATERIALS AND METHODS

This survey study was anonymous and gathered opinions of individuals who participate in the process to provide wheelchairs and other assistive technologies to clients. Participants were asked to rank the importance of developing various technologies and rank items against each other in terms of order of importance. Participants were also asked to respond to several open-ended questions or statements.

RESULTS

A total of 161 providers from 35 states within the USA consented to participation and completed the survey.

CONCLUSIONS

This survey revealed themes of advanced wheelchair design, assistive robotics and intelligent systems, human machine interfaces and smart device applications. It also outlined priorities for researchers to provide continuing education to clients and providers. These themes will be used to develop research and development priorities. Implications for Rehabilitation • Research in advanced wheelchair design is needed to facilitate travel and environmental access with wheelchairs and to develop alternative power sources for wheelchairs.• New assistive robotics and intelligent systems are needed to help wheelchairs overcome obstacles or self-adjust, assist wheelchair navigation in the community, assist caregivers and transfers, and aid ambulation.• Innovations in human machine interfaces may help advance the control of mobility devices and robots with the brain, eye movements, facial gesture recognition or other systems.• Development of new smart devices is needed for better control of the environment, monitoring activity and promoting healthy behaviours.

Further Development of a Robotic-Assisted Transfer Device

Background: The task of performing transfers, such as from a wheelchair to a bed, has a high risk of injury to both the caregiver and the person being transferred. Although mechanical transfer devices can reduce these risks, these devices are not meant for use in the community and they still place strain on the caregiver when used. Purpose: The aim of this study is to describe feedback gathered from focus groups of potential users of the Robotic-Assisted Transfer Device (RATD) and describe design changes aimed at preparing the device for the next step in the development process. Method: The RATD was transferred to a newer electric-powered wheelchair (EPW), key components were redesigned, and the control program was updated to increase the safety of the device. Two focus groups, one consisting of people with disabilities and the other consisting of clinicians and caregivers, were conducted to gather feedback from potential users. Results: Error checking, safety zones, a motor brake, and a new track helped increase the safety of the device. Sixty-three percent of the people with disabilities and 83% of caregivers surveyed said they would use the device. Conclusions: The results from the focus groups were positive and the design changes were successful, but more development is needed before the RATD can be marketed.

Kinematics and Stability Analysis of a Novel Power Wheelchair When Traversing Architectural Barriers

Background: Electric-powered wheelchairs (EPWs) are essential devices for people with disabilities for mobility and quality of life. However, the design of common EPWs makes it challenging for users to overcome architectural barriers, such as curbs and steep ramps. Current EPWs lack stability, which may lead to tipping the EPW causing injury to the user. An alternative Mobility Enhancement Robotic Wheelchair (MEBot), designed at the Human Engineering Research Laboratories (HERL), was designed to improve the mobility of, and accessibility for, EPW users in a wide variety of indoor and outdoor environments. Seat height and seat inclination can be adjusted using pneumatic actuators connected to MEBot's 6 wheels. Method: This article discusses the design and development of MEBot, including its kinematics, stability margin, and calculation of the center of mass location when performing its mobility applications of curb climbing/descending and attitude control. Motion capture cameras recorded the seat angle and joint motion of the 6 wheel arms during the curb climbing/descending process. The center of mass location was recorded over a force plate for different footprint configurations. Results: Results showed that the area of the footprint changed with the location of the wheels during the curb climbing/descending and attitude control applications. The location of the center of mass moved ±30 mm when the user leaned sideways, and the seat roll and pitch angle were 0° and ±4.0°, respectively, during curb climbing and descending. Conclusion: Despite the user movement and seat angle change, MEBot maintained its stability as the center of mass remained over the wheelchair footprint when performing its mobility applications.

Consumer Feedback to Steer the Future of Assistive Technology Research and Development: A Pilot Study

Objective: The overall objective of this project was to identify consumers' opinions of their needs and wants related to assistive technology (AT) in a systematic and quantitative manner via a questionnaire that can be used to validate existing and establish new research priorities. Methods: This pilot study describes questionnaire development, online implementation, and revisions considered to the questionnaire in preparation for conducting a nationwide survey. Data from a sample (N = 112) are presented. The pilot study was critical to refine the questions and ensure that meaningful information was being collected. Results: It was identified that revisions were warranted to provide more structure and allow for consumers to prioritize AT research efforts. Conclusion: The questionnaire results, although positively in favor of many of the technologies presented, are inconclusive to identify generalizable research priorities, thus expansion to a nationwide population is warranted.

Performance Evaluation of a Mobile Touchscreen Interface for Assistive Robotic Manipulators: A Pilot Study

Background: Assistive robotic manipulators (ARMs) have been developed to provide enhanced assistance and independence in performance of daily activities among people with spinal cord injury when a caregiver is not on site. However, the current commercial ARM user interfaces (UIs) may be difficult to learn and control. A touchscreen mobile UI was developed to overcome these challenges. Objective: The object of this study was to evaluate the performance between 2 ARM UIs, touchscreen and the original joystick, using an ARM evaluation tool (ARMET). Methods: This is a pilot study of people with upper extremity impairments (N = 8). Participants were trained on 2 UIs, and then they chose one to use when performing 3 tasks on the ARMET: flipping a toggle switch, pushing down a door handle, and turning a knob. Task completion time, mean velocity, and open interviews were the main outcome measurements. Results: Among 8 novice participants, 7 chose the touchscreen UI and 1 chose the joystick UI. All participants could complete the ARMET tasks independently. Use of the touchscreen UI resulted in enhanced ARMET performance (higher mean moving speed and faster task completion). Conclusions: Mobile ARM UIs demonstrated easier learning experience, less physical effort, and better ARMET performance. The improved performance, the accessibility, and lower physical effort suggested that the touchscreen UI might be an efficient tool for the ARM users.

Psychological strategies of Veterans and service members who participate in organized sports

Introduction: The study sought to examine the performance strategies of wounded, ill, and injured service members and Veterans who participate in the Warrior Games. Methods: The Test of Performance Strategies (TOPS) was completed by 23 men and 5 women participants on the first and last days of the Warrior Games. The participants were separated into 2 groups: those who had participated in organized sporting events for more than 1 year (experienced; n=14) and those who had less than 1 year of experience (novice; n=14). A mixed-model ANOVA was used to assess pre–post changes and the effect of experience on total TOPS scores. Results: Overall participation in the Warrior Games did not change the performance strategies used by the participants. However, experienced participants had higher post-competition sub-scale scores than novice participants in the categories of self-talk, goal setting, and activation ( p<0.05). Discussion: While participation in a single Warrior Games event did not appear to change participants' short-term psychological thought processes around competition and practice, more than 1 year of participation in organized sporting events was associated with improved skills.

Full-participation of students with physical disabilities in science and engineering laboratories

PURPOSE

To conduct a literature review identifying barriers and facilitators students with physical disabilities (SwD-P) may encounter in science and engineering (S&E) laboratories.

METHOD

Publications were identified from 1991 to 2015 in ERIC, web of science via web of knowledge, CINAHL, SCOPUS, IEEEXplore, engineering village, business source complete and PubMed databases using search terms and synonyms for accommodations, advanced manufacturing, additive manufacturing, assistive technology (AT), barriers, engineering, facilitators, instructor, laboratory, STEM education, science, students with disabilities and technology.

RESULTS

Twenty-two of the 233 publications that met the review's inclusion criteria were examined. Barriers and facilitators were grouped based on the international classification of functioning, disability and health framework (ICF). None of the studies directly found barriers or facilitators to SwD-P in science or engineering laboratories within postsecondary environments. The literature is not clear on the issues specifically related to SwD-P.

CONCLUSION

Given these findings, further research (e.g., surveys or interviews) should be conducted to identify more details to obtain more substantial information on the barriers that may prevent SwD-P from fully participating in S&E instructional laboratories. Implications for Rehabilitation Students with disabilities remain underrepresented going into STEM careers. A need exist to help uncover barriers students with disabilities encounter in STEM laboratory. Environments. Accommodations and strategies that facilitate participation in STEM laboratory environments are promising for students with disabilities.

Development of a wheelchair maintenance training programme and questionnaire for clinicians and wheelchair users

Purpose of state: The aims of this study were to develop a Wheelchair Maintenance Training Programme (WMTP) as a tool for clinicians to teach wheelchair users (and caregivers when applicable) in a group setting to perform basic maintenance at home in the USA and to develop a Wheelchair Maintenance Training Questionnaire (WMT-Q) to evaluate wheelchair maintenance knowledge in clinicians, manual and power wheelchair users.

METHODS

The WMTP and WMT-Q were developed through an iterative process.

RESULTS

A convenience sample of clinicians (n = 17), manual wheelchair (n ∞ 5), power wheelchair users (n = 4) and caregivers (n = 4) provided feedback on the training programme. A convenience sample of clinicians (n = 38), manual wheelchair (n = 25), and power wheelchair users (n = 30) answered the WMT-Q throughout different phases of development. The subscores of the WMT-Q achieved a reliability that ranged between ICC(3,1) = 0.48 to ICC(3,1) = 0.89. The WMTP and WMT-Q were implemented with 15 clinicians who received in-person training in the USA using the materials developed and showed a significant increase in all except one of the WMT-Q subscores after the WMTP (p < 0.007).

CONCLUSION

The WMTP will continue to be revised as it is further implemented. The WMT-Q is an acceptable instrument to measure pre- and post-training maintenance knowledge. Implications for Rehabilitation The Wheelchair Maintenance Training Program can be used to educate rehabilitation clinicians and technicians to improve wheelchair service and delivery to end users. This training complements the World Health Organization basic wheelchair service curriculum, which only includes training of the clinicians, but does not include detailed information to train wheelchair users and caregivers. This training program offers a time efficient method for providing education to end users in a group setting that may mitigate adverse consequences resulting from wheelchair breakdown. This training program has significant potential for impact among wheelchair users in areas where access to repair services is limited.

Power seat function usage and wheelchair discomfort for power wheelchair users

OBJECTIVES

To investigate correlations between power seat functions (PSFs) usage and wheelchair discomfort.

DESIGN

Quasi-experimental design: Time series design.

SETTING

In-home trial in participants' home/community.

PARTICIPANTS

Thirteen power wheelchair users who independently used power wheelchairs equipped with PSFs as their primary means of mobility.

MAIN OUTCOME MEASURES

PSF usage variables include the frequency of performing repositioning and using PSFs (tilt, recline, legrests and seat elevation), wheelchair occupancy, and driving distance. The Tool for Assessing Wheelchair disComfort (TAWC) were used to evaluate general discomfort and discomfort intensity.

RESULTS

Spearman correlation coefficient showed that the frequency of using tilt, recline, and legrest is significantly correlated with discomfort intensity. Multiple regression analysis with backward stepwise indicated that these functions can explain 43.8% of the variance (R2 = .438, F(3,33) = 8.588, P < 0.01) in the discomfort intensity score. The best-first decision tree shows that the frequency of using the legrest function was the top node, followed by recline and tilt functions. The overall accuracy of prediction with ten-fold cross validation for discomfort intensity was 79.4%.

CONCLUSIONS

For people who used power wheelchairs equipped with PSFs, correlation analysis and regression modeling provided evidence from the quantitative data that increasing the frequency of using PSFs may decrease wheelchair discomfort. Future studies should include interventions to encourage people to use their PSFs appropriately.

Step-Climbing Power Wheelchairs: A Literature Review

Background: Power wheelchairs capable of overcoming environmental barriers, such as uneven terrain, curbs, or stairs, have been under development for more than a decade. Method: We conducted a systematic review of the scientific and engineering literature to identify these devices, and we provide brief descriptions of the mechanism and method of operation for each. We also present data comparing their capabilities in terms of step climbing and standard wheelchair functions. Results: We found that all the devices presented allow for traversal of obstacles that cannot be accomplished with traditional power wheelchairs, but the slow speeds and small wheel diameters of some designs make them only moderately effective in the basic area of efficient transport over level ground and the size and configuration of some others limit maneuverability in tight spaces. Conclusion: We propose that safety and performance test methods more comprehensive than the International Organization for Standards (ISO) testing protocols be developed for measuring the capabilities of advanced wheelchairs with step-climbing and other environment-negotiating features to allow comparison of their clinical effectiveness.

Commentary on WHO GATE Initiative

Assistive technology is essential to people with spinal cord injuries (SCI) for living and participating in their communities. However, many people with SCI do not have access to adequate assistive technology and qualified services. The World Health Organization (WHO) is addressing this need through the Global Cooperation on Assistive Technology (GATE). The GATE initiative is focused on improving access to high-quality affordable AT world-wide. GATE working to meet the AT sector needs in response to the call by WHO to increase access to essential, high-quality, safe, effective and affordable medical devices, which is one of the six WHO leadership priorities.

The Experiential Learning for Veterans in Assistive Technology and Engineering (ELeVATE) program

Experiential Learning for Veterans in Assistive Technology and Engineering, or ELeVATE, is a program to assist wounded, injured, and ill Veterans in transitioning into university science, technology, engineering, and mathematics programs, with a special emphasis on assistive technology and engineering. This paper examines whether the ELeVATE model, by addressing academic preparation, professional development, rehabilitation counselling, and community reintegration, increases the academic success (defined as enrolling and excelling in a plan of study through a post-secondary institution) of transitioning Veterans with disabilities. Post-program surveys completed by seven participants indicated that they were satisfied with the efficacy of the program. Students rated the research paper and oral presentation of research, the networking seminar, and the resume writing workshop as “very helpful.” They found the group meetings with the vocational coordinator, the introduction to adaptive sports seminar, and the poster presentation to be “moderately helpful.” Seventy-one percent of the students indicated that being part of ELeVATE's supportive cohort of Veterans was “very” or “extremely” valuable. They rated the effectiveness of the support they provided to their peers higher than the support they received from their peers. Over time, ELeVATE participants demonstrated increased self-efficacy (via General Self-Efficacy instrument scores) to succeed in STEM and increased engagement in campus life (via National Survey of Student Engagement scores), and ELeVATE's impact even went beyond helping Veterans achieve their academic and personal goals.

Task-Oriented Performance Evaluation for Assistive Robotic Manipulators: A Pilot Study

OBJECTIVE

The objectives of this study were to evaluate the performance of commercially available assistive robotic manipulators (ARMs) user interfaces and to investigate the concurrent validity and sensitivity to change with task-oriented performance evaluation tools (TO-PETs) for ARMs.

DESIGN

This was a nonblinded randomized controlled study with power-wheelchair users with upper-extremity impairments (N = 10). Participants were trained to use 2 ARMs with their respective original user interfaces (keypad and joystick) and evaluated the performance using TO-PET and the adapted Wolf Motor Function Test (WMFT-ARM). Task completion time, ISO 9241-9 throughput, trajectory parameters, NASA-TLX, and questionnaires were the main outcome measurements. Concurrent validity and sensitivity were evaluated.

RESULTS

Statistical differences were found in ISO 9241-9 throughput between the 2 user interfaces for the single motion tasks and WMFT-ARM. However, there was no statistical difference found on the self-reported perceived workload and ease of use. Moderate to high correlation was found between the TO-PET and WMFT-ARM (P < 0.001). The TO-PET demonstrated higher Cohen d (0.910-1.085) than the WMFT-ARM.

CONCLUSIONS

The findings of this study provide a preliminary comparison between 2 commercial ARMs with their different user interfaces among novice ARM users. Recommendations for training and evaluation were revealed.

Evaluation of custom energy expenditure models for SenseWear armband in manual wheelchair users

Physical activity monitors are increasingly used to help the general population lead a healthy lifestyle by keeping track of their daily physical activity (PA) and energy expenditure (EE). However, none of the commercially available activity monitors can accurately estimate PA and EE in people who use wheelchairs as their primary means of mobility. Researchers have recently developed custom EE prediction models for manual wheelchair users (MWUs) with spinal cord injuries (SCIs) based on a commercial activity monitor--the SenseWear armband. This study evaluated the performance of two custom EE prediction models, including a general model and a set of activity-specific models among 45 MWUs with SCI. The estimated EE was obtained by using the two custom models and the default manufacturer's model, and it was compared with the gold standard measured by the K4b2 portable metabolic cart. The general, activity-specific, and default models had a mean signed percent error (mean +/- standard deviation) of -2.8 +/- 26.1%, -4.8 +/- 25.4%, and -39.6 +/- 37.8%, respectively. The intraclass correlation coefficient was 0.86 (95% confidence interval [CI] = 0.82 to 0.89) for the general model, 0.83 (95% CI = 0.79 to 0.87) for the activity-specific model, and 0.62 (95% CI = 0.16 to 0.81) for the default model. The custom models for the SenseWear armband significantly improved the EE estimation accuracy for MWUs with SCI.

A Patient-Controlled Analgesia Adaptor to Mitigate Postsurgical Pain for Combat Casualties With Multiple Limb Amputation: A Case Series

The use of explosive armaments during Operation Iraqi Freedom, Operation Enduring Freedom, and Operation New Dawn has resulted in a significant number of injured U.S. service members. These weapons often generate substantial extremity trauma requiring multiple surgical procedures to preserve life, limb, and restore function. For those individuals who require multiple surgeries, the use of patient-controlled analgesia (PCA) devices can be an effective way to achieve adequate pain management and promote successful rehabilitation and recovery during inpatient treatment. A subpopulation of patients are unable to independently control a PCA device because of severe multiple limb dysfunction and/or loss. In response to the needs of these patients, our team designed and developed a custom adaptor to assist service members who would otherwise not be able to use a PCA. Patient feedback of the device indicated a positive response, improved independence, and overall satisfaction during inpatient hospitalization.

Rehabilitation Medicine Summit: Building Research Capacity Executive Summary

The general objective of the “Rehabilitation Medicine Summit: Building Research Capacity” was to advance and promote research in medical rehabilitation by making recommendations to expand research capacity. The five elements of research capacity that guided the discussions were: (1) researchers; (2) research culture, environment, and infrastructure; (3) funding; (4) partnerships; and (5) metrics. The 100 participants included representatives of professional organizations, consumer groups, academic departments, researchers, governmental funding agencies, and the private sector. The small group discussions and plenary sessions generated an array of problems, possible solutions, and recommended actions. A post-Summit, multi-organizational initiative is called to pursue the agendas outlined in this report.

Evaluating the usability of a smartphone virtual seating coach application for powered wheelchair users

The aim of the smartphone virtual seating coach (SVSC) was to provide a personalized reminder/warning system to encourage powered wheelchair users to use their powered seating functions (PSFs) as clinically recommended. This study evaluated the usability of the SVSC system by gathering feedback from five powered wheelchair users and five rehabilitation professionals through questionnaires and interviews. The results indicated that clear and understandable instructions to adjust the PSFs are the most important requirement for SVSC application. The instructions must be intuitive, could benefit from animations or indications of PSFs control buttons so powered wheelchair users can adjust their PSFs immediately and appropriately.

Estimation of Energy Expenditure for Wheelchair Users Using a Physical Activity Monitoring System

OBJECTIVE

To develop and evaluate energy expenditure (EE) estimation models for a physical activity monitoring system (PAMS) in manual wheelchair users with spinal cord injury (SCI).

DESIGN

Cross-sectional study.

SETTING

University-based laboratory environment, a semistructured environment at the National Veterans Wheelchair Games, and the participants' home environments.

PARTICIPANTS

Volunteer sample of manual wheelchair users with SCI (N=45).

INTERVENTION

Participants were asked to perform 10 physical activities (PAs) of various intensities from a list. The PAMS consists of a gyroscope-based wheel rotation monitor (G-WRM) and an accelerometer device worn on the upper arm or on the wrist. Criterion EE using a portable metabolic cart and raw sensor data from PAMS were collected during each of these activities.

MAIN OUTCOME MEASURES

Estimated EE using custom models for manual wheelchair users based on either the G-WRM and arm accelerometer (PAMS-Arm) or the G-WRM and wrist accelerometer (PAMS-Wrist).

RESULTS

EE estimation performance for the PAMS-Arm (average error ± SD: -9.82%±37.03%) and PAMS-Wrist (-5.65%±32.61%) on the validation dataset indicated that both PAMS-Arm and PAMS-Wrist were able to estimate EE for a range of PAs with <10% error. Moderate to high intraclass correlation coefficients (ICCs) indicated that the EE estimated by PAMS-Arm (ICC3,1=.82, P<.05) and PAMS-Wrist (ICC3,1=.89, P<.05) are consistent with the criterion EE.

CONCLUSIONS

Availability of PA monitors can assist wheelchair users to track PA levels, leading toward a healthier lifestyle. The new models we developed can estimate PA levels in manual wheelchair users with SCI in laboratory and community settings.

Design and evaluation of a seat orientation controller during uneven terrain driving

Electric powered wheelchairs (EPWs) are essential devices for people with disabilities as aids for mobility and quality of life improvement. However, the design of currently available common EPWs is still limited and makes it challenging for the users to drive in both indoor and outdoor environments such as uneven surfaces, steep hills, or cross slopes, making EPWs susceptible to loss of stability and at risk for falls. An alternative wheel-legged robotic wheelchair, "MEBot", was designed to improve the safety and mobility of EPW users in both indoor and outdoor environments. MEBot is able to elevate its six wheels using pneumatic actuators, as well to detect changes in the seat angle using a gyroscope and accelerometer. This capability enables MEBot to provide sensing for a dynamic self-leveling seat application that can maintain the center of mass within the boundaries of the wheelchair, thereby, improving EPW safety. To verify the effectiveness of the application, MEBot was tested on a motion platform with six degrees of freedom to simulate different slopes that could be experienced by the EPW in outdoor environments. The results demonstrate the robustness of the application to maintain the wheelchair seat in a horizontal reference against changes in the ground angle.

The Influence of Glove Type on Simulated Wheelchair Racing Propulsion: A Pilot Study

Our purpose was to examine the influence of glove type on kinetic and spatiotemporal parameters at the handrim in elite wheelchair racers. Elite wheelchair racers (n=9) propelled on a dynamometer in their own racing chairs with a force and moment sensing wheel attached. Racers propelled at 3 steady state speeds (5.36, 6.26 & 7.60 m/s) and performed one maximal effort sprint with 2 different glove types (soft & solid). Peak resultant force, peak torque, impulse, contact angle, braking torque, push time, velocity, and stroke frequency were recorded for steady state and sprint conditions. Multiple nonparametric Wilcoxon matched pair's tests were used to detect differences between glove types, while effect sizes were calculated based on Cohen's d. During steady state trials, racers propelled faster, using more strokes and larger contact angle, while applying less impulse with solid gloves compared to soft gloves. During the sprint condition, racers achieved greater top end velocities, applying larger peak force, with less braking torque with solid gloves compared to soft gloves. Use of solid gloves may provide some performance benefits to wheelchair racers during steady state and top end velocity conditions.

Stability analysis of electrical powered wheelchair-mounted robotic-assisted transfer device

The ability of people with disabilities to live in their homes and communities with maximal independence often hinges, at least in part, on their ability to transfer or be transferred by an assistant. Because of limited resources and the expense of personal care, robotic transfer assistance devices will likely be in great demand. An easy-to-use system for assisting with transfers, attachable to electrical powered wheelchairs (EPWs) and readily transportable, could have a significant positive effect on the quality of life of people with disabilities. We investigated the stability of our newly developed Strong Arm, which is attached and integrated with an EPW to assist with transfers. The stability of the system was analyzed and verified by experiments applying different loads and using different system configurations. The model predicted the distributions of the system's center of mass very well compared with the experimental results. When real transfers were conducted with 50 and 75 kg loads and an 83.25 kg dummy, the current Strong Arm could transfer all weights safely without tip-over. Our modeling accurately predicts the stability of the system and is suitable for developing better control algorithms to enhance the safety of the device.

Improving Target Acquisition for Computer Users With Athetosis

Prior work has highlighted the challenges faced by people with athetosis when trying to acquire on-screen targets using a mouse or trackball. The difficulty of positioning the mouse cursor within a confined area has been identified as a challenging task. We have developed a target acquisition assistance algorithm that features transition assistance via directional gain variation based on target prediction, settling assistance via gain reduction in the vicinity of a predicted target, and expansion of the predicted target as the cursor approaches it. We evaluated the algorithm on improving target acquisition efficiency among seven participants with athetoid cerebral palsy. Our results showed that the algorithm significantly reduced the overall movement time by about 20%. Considering the target acquisition occurs countless times in the course of regular computer use, the accumulative effect of such improvements can be significant for improving the efficiency of computer interaction among people with athetosis.

Upper limb joint kinetics of three sitting pivot wheelchair transfer techniques in individuals with spinal cord injury

STUDY DESIGN

Repeated measures design.

OBJECTIVE

This study compared the upper extremity (UE) joint kinetics between three transfer techniques.

SETTING

Research laboratory.

METHODS

Twenty individuals with spinal cord injury performed three transfer techniques from their wheelchair to a level tub bench. Two of the techniques involved a head-hips method with leading hand position close (HH-I) and far (HH-A) from the body, and the third technique with the trunk upright (TU) and hand far from body. Motion analysis equipment recorded upper body movements and force sensors recorded their hand and feet reaction forces during the transfers.

RESULTS

Several significant differences were found between HH-A and HH-I and TU and HH-I transfers indicating that hand placement was a key factor influencing the UE joint kinetics. Peak resultant hand, elbow, and shoulder joint forces were significantly higher for the HH-A and TU techniques at the trailing arm (P < 0.036) and lower at the leading arm (P < 0.021), compared to the HH-I technique.

CONCLUSION

Always trailing with the same arm if using HH-A or TU could predispose that arm to overuse related pain and injuries. Technique training should focus on initial hand placement close to the body followed by the amount of trunk flexion needed to facilitate movement.

Adaptive sports technology and biomechanics: prosthetics

With the technologic advances in medicine and an emphasis on maintaining physical fitness, the population of athletes with impairments is growing. It is incumbent upon health care practitioners to make every effort to inform these individuals of growing and diverse opportunities and to encourage safe exercise and athletic participation through counseling and education. Given the opportunities for participation in sports for persons with a limb deficiency, the demand for new, innovative prosthetic designs is challenging the clinical and technical expertise of the physician and prosthetist. When generating a prosthetic prescription, physicians and prosthetists should consider the needs and preferences of the athlete with limb deficiency, as well as the functional demands of the chosen sporting activity. The intent of this article is to provide information regarding the current advancements in the adaptive sports technology and biomechanics in the field of prosthetics, and to assist clinicians and their patients in facilitating participation in sporting activities.

Biofilms in wounds: a review of present knowledge

Following confirmation of the presence of biofilms in chronic wounds, the term biofilm became a buzzword within the wound healing community. For more than a century pathogens have been successfully isolated and identified from wound specimens using techniques that were devised in the nineteenth century by Louis Pasteur and Robert Koch. Although this approach still provides valuable information with which to help diagnose acute infections and to select appropriate antibiotic therapies, it is evident that those organisms isolated from clinical specimens with the conditions normally used in diagnostic laboratories are mainly in a planktonic form that is unrepresentative of the way in which most microbial species exist naturally. Usually microbial species adhere to each other, as well as to living and non-living surfaces, where they form complex communities surrounded by collectively secreted extracellular polymeric substances (EPS). Cells within such aggregations (or biofilms) display varying physiological and metabolic properties that are distinct from those of planktonic cells, and which contribute to their persistence. There are many factors that influence healing in wounds and the discovery of biofilms in chronic wounds has provided new insight into the reasons why. Increased tolerance of biofilms to antimicrobial agents explains the limited efficacy of antimicrobial agents in chronic wounds and illustrates the need to develop new management strategies. This review aims to explain the nature of biofilms, with a view to explaining their impact on wounds.

Rehabilitation Medicine Summit: Building Research Capacity

The general objective of the "Rehabilitation Medicine Summit: Building Research Capacity" was to advance and promote research in medical rehabilitation by making recommendations to expand research capacity. The five elements of research capacity that guided the discussions were 1) researchers; 2) research culture, environment, and infrastructure; 3) funding; 4) partnerships; and 5) metrics. The 100 participants included representatives of professional organizations, consumer groups, academic departments, researchers, governmental funding agencies, and the private sector. The small group discussions and plenary sessions generated an array of problems, possible solutions, and recommended actions. A post-Summit, multi-organizational initiative is called to pursue the agendas outlined in this report.

Advanced Joystick Algorithms for Computer Access Tasks

OBJECTIVE

To compare 2 correction algorithms and 2 joysticks (a conventional movement-sensing joystick and a custom-designed isometric joystick) in computer access tasks.

DESIGN

Repeated-measures, within-subject.

SETTING

National Veterans Wheelchair Games.

PARTICIPANTS

Fifteen participants with various diagnoses including multiple sclerosis, spinal cord injury, traumatic brain injury, Wilson disease, and Parkinson disease.

METHODS

A computer access test scenario was used to evaluate the effects of applying proportional integral derivative (PID)-based and least means-based algorithms to suppress unintentional cursor motions by users with upper extremity spasticity.

MAIN OUTCOME MEASURES

Trial completion time, reaction time, and trajectory-based measures: movement offset, movement variability, and percentage of out-of-path motion on test tracks.

RESULTS

The quantitative outcome measures showed a high correlation with clinical measures for spasticity and functional independence. On small test tracks, compared to when no correction algorithms were used, both algorithms performed equally well in suppressing unintentional cursor motions. On longer test tracks, participants navigated most accurately while using the PID algorithm. Participants moved the cursor more accurately using the isometric joystick compared to the movement-sensing joystick, with only a slight increase in the task completion times.

CONCLUSIONS

The joysticks and the advanced correction algorithms show promise for use in wide-ranging applications as control interfaces.

Using the Kinect to limit abnormal kinematics and compensation strategies during therapy with end effector robots

Abnormal kinematics and the use of compensation strategies during training limit functional improvement from therapy. The Kinect is a low cost ($100) sensor that does not require any markers to be placed on the user. Integration of this sensor into currently used therapy systems can provide feedback about the user's movement quality, and the use of compensatory strategies to complete tasks. This paper presents a novel technique of adding the Kinect to an end effector robot to limit compensation strategies and to train normal joint coordination during movements with an end effector robot. This methodology has wider implications for other robotic and passively actuated end effector rehabilitation devices.

Detection of physical activities using a physical activity monitor system for wheelchair users

Availability of physical activity monitors for wheelchair users can potentially assist these individuals to track regular physical activity (PA), which in turn could lead to a healthier and more active lifestyle. Therefore, the aim of this study was to develop and validate algorithms for a physical activity monitoring system (PAMS) to detect wheelchair based activities. The PAMS consists of a gyroscope based wheel rotation monitor (G-WRM) and an accelerometer device (wocket) worn on the upper arm or on the wrist. A total of 45 persons with spinal cord injury took part in the study, which was performed in a structured university-based laboratory environment, a semi-structured environment at the National Veterans Wheelchair Games, and in the participants' home environments. Participants performed at least ten PAs, other than resting, taken from a list of PAs. The classification performance for the best classifiers on the testing dataset for PAMS-Arm (G-WRM and wocket on upper arm) and PAMS-Wrist (G-WRM and wocket on wrist) was 89.26% and 88.47%, respectively. The outcomes of this study indicate that multi-modal information from the PAMS can help detect various types of wheelchair-based activities in structured laboratory, semi-structured organizational, and unstructured home environments.

Clinical impact of FDG PET-CT on the management of patients with locally advanced cervical carcinoma

AIM

To evaluate the impact of staging FDG PET-CT on the initial management of patients with locally advanced cervical carcinoma (LACC) and any prognostic variables predicting survival.

MATERIALS AND METHODS

Retrospective analysis of consecutive patients undergoing FDG PET-CT for staging of LACC in a single tertiary referral centre, between April 2008 and August 2011. Comparison was made between MRI and PET-CT findings and any subsequent impact on treatment intent or radiotherapy planning was evaluated.

RESULTS

Sixty-three patients underwent FDG PET-CT for initial staging of LACC. Major impact on management was found in 20 patients (32%), a minor impact in five (8%), and no impact in 38 (60%). In those patients where PET-CT had a major impact, 12 had more extensive local nodal involvement, five had occult metastatic disease, two had synchronous tumours, and one patient had equivocal lymph nodes on MRI characterized as negative. PET-positive nodal status at diagnosis was found to be a statistically significant predictor of relapse-free survival (p < 0.05).

CONCLUSION

Staging FDG PET-CT has a major impact on the initial management of approximately one-third of patients with LACC by altering treatment intent and/or radiotherapy planning. PET-defined nodal status is a poor prognostic indicator.

Comfort and stability of wheelchair backrests according to the TAWC (tool for assessing wheelchair discomfort)

PURPOSE

The goal of this study was thus to determine if people with different types of wheelchair backrests on their personal wheelchairs reported different levels of comfort as measured by the Tool for Assessing Wheelchair disComfort (TAWC).

METHODS

Participants were between 18 and 80 years of age and were manual wheelchair users. The TAWC was used to assess the participants' wheelchair seating discomfort levels with the wheelchair and seating systems.

RESULTS

We surveyed 131 wheelchair users to assess the comfort of their backrests on their personal wheelchairs and found a trend suggesting that rigid backrests are were less comfortable as compared with sling backrests. This finding was statistically significant in a subgroup of participants with tetraplegia.

CONCLUSIONS

Although many clinicians expect rigid backrests to be more comfortable because they may provide more support, the higher discomfort ratings among rigid backrest users with tetraplegia may be due to sub-optimal shape, fit, adjustment or user preferences. Implications for Rehabilitation Development of a measure for long-term seating discomfort is needed. Design and development of better rigid backrests that are functional but provide adequate comfort are in need.

Design, testing and evaluation of angle-adjustable backrest hardware

PURPOSE

The purpose of this study was to design and evaluate a final design prototype of angle-adjustable backrest hardware.

METHODS

A traditional iterative design development protocol was undertaken and completed. Before evaluation by a focus group, testing of the prototype was performed in strict accordance with ISO standards. Focus group participants were between 18 and 80 years of age, used a manual wheelchair as their primary means of mobility, and transferred independently. Individuals with pressure sores or who required of the use of specialized or custom seating for trunk support were excluded from the study. A questionnaire was administered to elicit participants' opinions on the adjustability, function and appearance of the angle-adjustable backrest device.

RESULTS

The prototype successfully met the ISO testing standards. Wheelchair users (n = 8) who evaluated the device in a focus group had an overall positive response. Things they most liked about the prototype were comfort, support (function/activities) and adjustability, while things they most disliked about the prototype were problems with string and reaching back position to adjust.

CONCLUSIONS

The prototype had a positive impression from participants, however, improvements on the operation method and usability were suggested. Implications for Rehabilitation The adjustable backrest is in need of development to provide function, comfort and support for manual wheelchair users. Manual wheelchair users will benefit by using the angle adjustment as they maintain their active lifestyles. Balance control while performing pressure relief in a wheelchair would be increased.

Measuring static seated pressure distributions and risk for skin pressure ulceration in ice sledge hockey players

PURPOSE

To determine whether sledge hockey players with physical disability have higher average seated pressures compared to non-disabled controls.

METHOD

Fifteen age-matched controls without physical disability and 15 experimental participants with physical disability were studied using a pressure mapping device to determine risk for skin pressure ulceration and the impact of cushioning and knee angle positioning on seated pressure distributions.

RESULTS

Regardless of participant group, cushioning, or knee angle, average seated pressures exceeded clinically acceptable seated pressures. Controls had significantly higher average seated pressures than the disability group when knees were flexed, both with the cushion (p = 0.013) and without (p = 0.015). Knee extension showed significantly lower average pressures in controls, both with the cushion (p < 0.001) and without (p < 0.001). Placement of the cushion resulted in significantly lower average pressure in controls when knees were extended (p = 0.024) but not when flexed (p = 0.248). Placement of the cushion resulted in no difference in pressure (p = 0.443) in the disability group.

CONCLUSIONS

Pressures recorded indicate high risk for skin ulceration. Cushioning was effective only in the control group with knees extended. That knee extension significantly lowered average seated pressures is important, as many sledge hockey players utilize positioning with larger knee flexion angles. Implications for Rehabilitation Ice sledge hockey is a fast growing adaptive sport. Adaptive sports have been associated with several positive improvements in overall health and quality of life, though may be putting players at risk for skin ulceration. Measured static seated pressure in sledges greatly exceeds current clinically accepted clinical guidelines. With modern improvements in wheelchair pressure relief/cushioning there are potential methods for improvement of elevated seated pressure in ice hockey sledges.

Evaluation of lightweight wheelchairs using ANSI/RESNA testing standards

Lightweight wheelchairs are characterized by their low cost and limited range of adjustment. Our study evaluated three different folding lightweight wheelchair models using the American National Standards Institute/Rehabilitation Engineering Society of North America (ANSI/RESNA) standards to see whether quality had improved since the previous data were reported. On the basis of reports of increasing breakdown rates in the community, we hypothesized that the quality of these wheelchairs had declined. Seven of the nine wheelchairs tested failed to pass the multidrum test durability requirements. An average of 194,502 +/- 172,668 equivalent cycles was completed, which is similar to the previous test results and far below the 400,000 minimum required to pass the ANSI/RESNA requirements. This was also significantly worse than the test results for aluminum ultralight folding wheelchairs. Overall, our results uncovered some disturbing issues with these wheelchairs and suggest that manufacturers should put more effort into this category to improve quality. To improve the durability of lightweight wheelchairs, we suggested that stronger regulations be developed that require wheelchairs to be tested by independent and certified test laboratories. We also proposed a wheelchair rating system based on the National Highway Transportation Safety Administration vehicle crash ratings to assist clinicians and end users when comparing the durability of different wheelchairs.

Evaluation of scooters using ANSI/RESNA standards

To date, only one research study has evaluated how scooters respond to static and dynamic stability. However, no other studies have evaluated how scooters respond to adverse conditions and how they perform in all standard tests. A selection of 12 three-wheeled scooters was tested according to American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society of North America (ANSI/ RESNA) wheelchair standards. Scooter models included the Victory, Gogo, Golden Companion (GC) I, and GC II. Victory and GC II were the most stable scooters. The Gogo scooters were the least dynamically stable. Five scooters (3 Gogo, 1 GC I, 1 GC II) failed the environmental condition tests. All GC I and II scooters failed parts of the power and control system tests. All scooters passed static and impact tests; however, all Gogo scooters and one GC II scooter had structural or motor failure during durability tests. The scooter models' survival life ranged from 62,512 to 1,178,230 cycles out of the 400,000 needed to pass the test. Tiller failures (typically tiller tube snapping) occurred with an average of 1,483 N force applied to the tiller structure. Our results indicate that these commercially available devices may not meet ANSI/RESNA standards. In addition, the tiller test should be conducted with scooters to further ensure their safety and durability and should use a test dummy with weight capacity according to the mobility device capacity.

Effect of low-compression balls on wheelchair tennis match-play

The purpose of this study was to compare court-movement variables and physiological responses to wheelchair tennis match-play when using low vs. standard compression tennis balls. Eleven wheelchair basketball players were monitored during repeated bouts of tennis (20 min) using both ball types. Graded and peak exercise tests were completed. For match-play, a data logger was used to record distance and speed. Individual linear heart rate oxygen consumption relationships were used to estimate match-play oxygen uptake. Significant main effects for ball type revealed that total distance (P<0.05), forward distance (P<0.05), and average speed (P<0.05) were higher for play using a low-compression ball. A lower percentage of total time was spent stationary (P<0.001), with significantly more time spent at speeds of 1-1.49 (P<0.05), 1.5-1.99 (P<0.05) and 2.0-2.49 (P<0.05) m ∙ sec(-1) when using the low-compression ball. Main effects for physiological variables were not significant. Greater total and forward distance, and higher average speeds are achieved using a low-compression ball. The absence of any difference in measured HR and estimated physiological responses would indicate that players move further and faster at no additional mean physiological cost. This type of ball will be useful for novice players in the early phases of skill development.

Pressure mapping to assess seated pressure distributions and the potential risk for skin ulceration in a population of sledge hockey players and control subjects

PURPOSE

Ice sledge (or sled) hockey is a fast-paced sport that enables individuals with physical disabilities to play ice hockey. As the attraction to the sport continues to rise, the need for developing better equipment and installing preventative measures for injury will become increasingly important. One such injury includes skin pressure ulceration.

METHOD

A total of 26 subjects including active controls and those with spinal cord injury, multiple sclerosis, limb amputation and traumatic brain injury were studied using a pressure mapping device at the 2012 National Disabled Veterans Winter Sports Clinic to determine the risk for skin pressure ulceration and the impact of cushioning and knee angle positioning on seated pressure distributions.

RESULTS

Sledge hockey athletes may be at increased risk for skin pressure ulceration based on seated pressure distribution data. This experiment failed to demonstrate a benefit for specialty cushioning in either group. Interestingly, knee angle positioning, particularly, knee extension significantly lowered the average seated pressures.

CONCLUSIONS

When considering the risk for skin pressure ulceration, knee angle positioning is of particular clinical importance. More research is warranted, specifically targeting novel cushion and sledge designs and larger groups of individuals with sensory loss and severe spinal deformities. Implications for Rehabilitation Ice sledge (or sled) hockey is a fast-paced and growing adaptive sport played at the Paralympic level. Rehabilitation professionals should consider the potential for skin ulceration in this population of athletes. The effects of cushioning used in the sledge design warrants further investigation. Knee angle positioning; particularly, knee extension significantly lowers seated pressures and may reduce the potential for skin ulceration.